The evolution of the conventional public switched telephone network has resulted in a variety of voice applications and services that can be provided to individual subscribers and business subscribers. Such services include voice messaging systems that enable landline or wireless subscribers to record, playback, and forward voice mail messages. However, the ability to provide enhanced services to subscribers of the public switched telephone network is directly affected by the limitations of the public switched telephone network. In particular, the public switched telephone network operates according to a protocol that is specifically designed for the transport of voice signals; hence any modifications necessary to provide enhanced services can only be done by switch vendors that have sufficient know-how of the existing public switched telephone network infrastructure.
An open standards-based Internet protocol (IP) network, such as the World Wide Web, the Internet, or a corporate intranet, provides client-server type application services for clients by enabling the clients to request application services from remote servers using standardized protocols, for example, the hypertext transport protocol (HTTP). The web server application environment can include web server software, such as Apache, implemented on a computer system attached to the IP network. Web-based applications are composed of HTML (Hypertext Markup Language) pages, logic, and database functions. In addition, the web server may provide logging and monitoring capabilities.
In contrast to the public switched telephone network, the open standards-based IP network has enabled the proliferation of web based applications written by web application developers using web development tools. Hence, the ever increasing popularity of conventional web applications and web development tools provides substantial resources for application developers to develop robust web applications in a relatively short time and in an economical manner. However, one important distinction between telephony-based applications and web-based applications is that telephony-based applications are state aware, whereas web-based applications are stateless.
In particular, conventional telephony applications are state aware to ensure that prescribed operations between the telephony application servers and the user telephony devices occur in a prescribed sequence. For example, operations such as call processing operations, voicemail operations, call forwarding, etc., require that specific actions occur in a specific sequence to enable the multiple components of the public switched telephone network to complete the prescribed operations.
The prior art web-based applications running in the IP network, however, are state-less and transient in nature, and do not maintain application state because application state requires an interactive communication between the browser and back-end database servers accessed by the browsers via a HTTP-based web server. However, an HTTP server provides asynchronous execution of HTML applications, where the web applications in response to reception of a specific request in the form of a URL (Uniform Resource Locator) from a client, instantiate a program configured for execution of the specific request, send an HTML web page back to the client, and terminate the program instance that executed the specific request. Storage of application state information in the form of a “cookie” is not practical because some users prefer not to enable cookies on their browser, and because the passing of a large amount of state information as would normally be required for voice-type applications between the browser and the web application would substantially reduce the bandwidth available for the client.
Referring now to conventional approaches used to track and monitor events of significance to a user of some service, in one approach the user actively checks or monitors data to determine if some event occurred of significance to the user. For example, the user opens a web browser and accesses a web site to check on when packages are likely to be delivered to or picked up from the user's office, or whether a user's overnight delivery package has been delivered to an intended recipient. The user can use the packages identification number or other information to check the web site to determine when and where the package was delivered. The user can also use the web site, or call the overnight deliver service provider, to determine when a package will be picked up for outgoing delivery.
In another conventional approach, a user can be contacted by an individual calling the user over a telephone. For example, a stock broker can initiate a phone call to the user when a stock has reached a low price level to discuss with the user whether to buy the stock or not.
In another example, the user accesses a web site to check on a current stock quote price. For example, a user can access a commercial web site, such as the Yahoo!™, currently located at www.yahoo.com, provided by Yahoo! Inc., Santa Clara, Calif. The user can request a stock quote. The web site then locates the latest stock quote for the stock in question, and presents it to the user via a web page provided to the user and displayed on the user's local browser. The user then decides whether to purchase the stock, either through a link associated with the web site, or by contacting a stock broker independently from the web site, such as by contacting the stock broker by telephone.